Method push

11. Stack/Stack Using Array.cpp:21–42

        return this->size;
    }
    void push(int element)
    {
        if(this->size == this->capacity)
        {
            capacity *= 2 ;
            int *a = new int[capacity] ;
            for(int i=0;i<this->size;i++)
                a[i+1] = this->a[i] ;
            //delete this->[]a ;
            this->a = a ;
            delete a ;
            this->a[0] = element ;
            size++ ;
        }
        else
        {
            for(int i=size;i>0;i--)
                this->a[i] = this->a[i-1] ;
            this->a[0] = element ;
            size++ ;
        }
    }
    int top()
    {
        if(this->size == 0)